ALPHA & OMEGA SEMICONDUCTOR Ltd

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

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NOTICE OF 2025 ANNUAL GENERAL MEETING OF SHAREHOLDERS

NOTICE IS HEREBY GIVEN that the 2025 Annual General Meeting of Shareholders (the “Annual Meeting”) of Alpha and Omega Semiconductor Limited, a Bermuda exempted limited liability company (“we,” “our,” “us,” or the “Company”), will be held at 8:00 a.m. on Wednesday, November 12, 2025 Taiwan local time (at 4:00 p.m. on Tuesday, November 11, 2025, U.S. Pacific Standard Time), at the Illume Taipei Hotel, No. 100, Dun Hua N Rd., Songshan District, Taipei City, Taiwan, or any other adjournments or postponements thereof, for the following purposes:

1. To elect nine (9) nominees to serve as directors on the Board of Directors of the Company (the “Board”) until the next annual general meeting of shareholders or until their successors are duly elected and qualified;

2. To approve, on an advisory basis, the compensation of the Company’s named executive officers, as described in this Proxy Statement;

3. To approve an amendment and restatement of the Company’s 2018 Omnibus Incentive Plan to, among other things, increase the number of common shares authorized for issuance under such plan from 4,609,000 shares to 5,202,000 shares;

4. To approve and ratify the appointment of Deloitte & Touche, LLP as the Company’s independent registered public accounting firm, and to authorize the Board, acting through our Audit Committee, to determine the remuneration of such accounting firm, for the fiscal year ending June 30, 2026; and

5. To approve the adjournment of the Annual Meeting to a later date, if necessary or appropriate, to permit further solicitation and vote of proxies in the event that there are insufficient votes for the approval of the other proposals contained herein.

Only holders of common shares of record at the close of business on September 12, 2025, which is the record date for the Annual Meeting, will be entitled to vote at the Annual Meeting and any continuation or adjournment thereof. Your vote is very important. Regardless of whether you plan to attend the Annual Meeting, it is important that your shares be represented and voted at the Annual Meeting, and we hope you will vote as soon as possible. Voting over the Internet or by telephone, by written proxy or voting instruction card will ensure your representation at the Annual Meeting regardless of whether you attend the Annual Meeting.

By order of the Board of Directors,

Mike F. Chang

Chairman of the Board of Directors

Dated September 18, 2025

Important Notice Regarding the Availability of Proxy Materials

For the Annual Meeting to be Held on November 12, 2025Taiwan Local Time

(November 11, 2025 U.S. Pacific Standard Time)

The Proxy Statement, Proxy Card and Annual Report on Form 10-K for fiscal year 2025 are available at:

http://www.investorvote.com/AOSL

PROXY STATEMENT

FOR THE 2025 ANNUAL GENERAL MEETING OF SHAREHOLDERS